The Andorians are the GR equivilant of Vulcans - quiet, logical, and very focoused on mental prowess. Waldo is hardly an exception, a brilliant mathmatician and engineer.
Waldo has a nephew nammed Nobus, and is close friends with fellow ambassador/scientist Tyko, and Tyko's wife, Thella(sp?).
Waldo won't use weapons (The scene in Mothmoose is not considered canon). Instead of fighting an enemy, he will let them charge, and come into contact with a forcefield he activates around himself. It's unclear (though very likely) as to whether or not Zozo and Waldo are the two "peaceful aliens" who came to Earth in the opening monologue.